This invention relates generally to a means and method for surgical anastomosis and more specifically to a means and method for performing sutureless surgical end-to-end anastomosis.
Severed blood vessels and other tubular fluid carrying body members requiring anastomosis are frequently encountered in penetrating wounds inflicted during combat, civil violence and automobile accidents. Other surgical procedures requiring anastomosis are the bypassing of blocked tubular members or replacement of a portion of a vessel or other tubular member with a portion of a vessel taken from another part of the body. Still another surgical procedure requiring anastomosis is the replacement of a damaged or diseased vessel or other tubular member with a prosthesis. At the present time, when these types of surgical procedures are necessary and when the requisite skills and facilities are available, the tubular members are anastomosed using a suturing procedure. As can be appreciated, the suturing of blood vessels or other tubular members requires exquisite skill and is a time consuming procedure. Under combat or emergency conditions, the requisite skills, facilities and time may not be available to prevent loss of limb or life.
The difficulties associated with anastomotic procedures are illustrated by examining the problems associated with vascular anastomosis. Arteries within man have three coats: the outer coat or tunica adventitia, consisting of a strong fibrous sheath; the middle coat or tunica media, consisting of muscular fibers; and the inner coat or tunica intima, consisting of a layer of elastic tissue lined with plate-like endothelial cells. When an artery is severed the muscular coat instantly contracts, drawing the cut end within the outer fibrous sheath so that a very small hole is left to be closed by blood clotting. Because of the constrictive response of the tunica media, a small artery usually can be severed without hemorrhaging. However, the same response may tend to inhibit reestablishment of patency if the vessel is rejoined.
The suturing process, in an anastomotic procedure, must be conducted by a surgeon specially trained in vascular surgery. Using a curved needle the sutures must be placed precisely, piercing the tunica adventitia from the outside and the tunica intima from the inside in the exact locations for proper vessel approximation (tunica intima aligned and in good contact). Either individual or a continuous running suture are used. The suturing procedure, as can be appreciated, is an extremely time consuming process. For small vascular members, the suturing procedure must be conducted under magnification by a surgeon trained in microvascular anastomosis. Typically, for an artery with a 3 mm lumen approximately 20 stitches must be taken around the circumference using a 6-0 (0.1 mm diameter) thread. It is usually not technically possible to perform a microvascular anastomosis in less than 30 minutes. Because of the time required for the anastomotic suturing procedure, the greatest success rate is achieved when anastomosis is performed in areas having a good collateral blood supply or in an area which can tolerate the loss of blood flow for the time required for the anastomotic suturing procedure. Inordinate time and skill is required to insure that the tunica intima of the two vessels being anastomosed are joined in intimate contact to prevent vascular occlusion and to insure proper healing of the vessel. A vascular occlusion at the site of anastomosis can lead to disastrous results including loss of life or limb.
Another problem area which is illustrative of the problem associated with sutures in an anastomotic procedure is intracranial surgery and the difficulties presented by the application of sutures to anastomose intracranial vessels. Cerebral arteries as compared to extracerebral vessels have less tunica adventitia, reduced tunica media and have many perforating branches which preclude the surgeon from rotating the vessel during the anastomotic suturing procedure. The limited time that intracranial vessels can be occluded without brain damage hamper and sometimes preclude the successful application of sutures to cerebral vessels.
Still another problem area which is further illustrative of the problem associated with sutures is the procedure of grafting a prosthesis to an existing vessel. It has been found that the clinical success of prosthetic grafts is dependent, to a large extent, on the suturing procedure. In other words, the suturing procedure is a major cause of failure of prosthetic grafts. The sutures must be properly made to avoid interfaces which cause tubulent flow and clotting. If the sutures are too tight or too closely spaced they produce necrotic areas. If the sutures are too loose or too far apart leakage occurs and early failure occurs. Additionally, it has been found that a strong fibrous bond does not develop between the graft and the vessel so that the union is dependent on the strength of the anastomotic suture. Because of the inherently weak junction coupled with fraying of the prostheses caused to a large part by the sutures, false aneurysms have been the cause of complications. This problem is aggravated when the conditions of the vessel are such that its ability to maintain sutures is impaired by degenerative disease. As a result, a number of techniques have been investigated to reinforce the suture line such as suturing reinforcing sleeves over the vessel-to-prosthetic junction. Furthermore, prostheses, depending on the type of material and the type of weave or knit, vary in their ability to hold sutures.
The prior art discloses a number of attempts to develop a sutureless technique to perform anastomosis. One method has employed tissue adhesives. Animal research, however, has shown that adhesive techniques are not satisfactory and often result in necrosis of the tunica media at the site of the junction, thrombosis, if any adhesive enters the lumen, and a high incidence of early hemorrhaging, "Handbook of Biomedical Plastics", Lee, Henry and Neville, Kris, Pasadena Technology Press, pages 4-14.
Other attempts to develop a successful sutureless anastomotic technique are represented by U.S. Pat. Nos. 3,221,746, 3,357,432, 3,648,295, 3,683,926 and 4,267,842. However, all of these feature an inner tube-like device placed inside the vessels to be anastomosed. As is known in the art, a constriction, irregularity or foreign material within the lumen of a blood vessel tends to cause a blood clot to form which may eventually occlude the vessel.
Still other attempts to develop a successful sutureless anastomotic technique are represented by U.S. Pat. Nos. 3,316,914, 3,774,615, 4,214,586 and 4,233,981. U.S. Pat. Nos. 3,316,914 and 4,233,981 both feature a pair of annular flanges. Pointed pins on one of the flanges are pierced through the vessel walls and are inserted into apertures in the other flange to hold and locate the vessel walls. The flanges in U.S. Pat. No. 4,233,981 are held in place by nuts and bolts. The flanges in U.S. Pat. No. 3,316,914 are held in place by sutures threaded through aligned holes on the flanges.
U.S. Pat. No. 3,774,615 discloses a device comprising a connecting ring over which the ends of the severed vessel are pulled and a fastening means to secure the severed vessel ends to the connecting ring. U.S. Pat. No. 4,214,586 discloses a three-piece coupling device comprising two open bore cylindrical adaptors and an open bore cylindrical connector. Each end of the vessel to be anastomosed are passed through the axial bore of an adaptor and everted over the end of the adaptor. The adaptors are then inserted into opposite ends of the connector until the everted ends of the vessel abut under light compression. Means integral to the adaptors and connector secure the device in place.
Other methods, including stapling, have been suggested to avoid the disadvantages of suturing. However, each of the proposed methods either have a complicated mechanical device that may be unadaptable in certain surgical situations, have a portion of the device within the vessel lumen or damage the vascular wall.
The ideal anastomotic technique should provide firm intimate contact between the inner coats of the members being anastomosed to prevent leakage while promoting healing, should not damage the vascular wall to prevent necrosis and a source of infection, should be completely external to the vascular lumen to prevent thrombi from forming, should provide fast and simple execution, should be able to be accomplished without rotation of the vessel or member being anastomosed, should require a lesser degree of skill than now required of vascular surgeons, on the part of the surgeon performing the anastomosis and should be able to be performed in a combat or emergency situation.
It is therefore one object of this invention to provide a sutureless anastomosis technique that is rapid, simple and that can be performed in a combat or emergency situation.
It is another object of this invention to provide a sutureless anastomosis technique that provides perfect adaptation of the members being anastomosed without damage to the walls of the members.
It is a further object of this invention to provide a sutureless anastomosis technique that is reliable and requires less skill on the part of a surgeon than anastomotic suturing and which can be performed in a combat or emergency situation.
It is still another object of this invention to provide a sutureless anastomosis technique that does not require the members being anastomosed to be rotated.
It is still a further object of this invention to provide a sutureless anastomosis technique that does not require any foreign object within the lumen of the members being anastomosed.
It is also another object of this invention to provide a sutureless anastomosis technique that is applicable to prosthetic grafts.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.